Objectives of this research project are (1) to characterize the dispersion and dilution of gaseous and small-particle aerosol contaminants within a confined, ventilated space that simulates a biomedical research laboratory, or other work space, and (2) to study the dispersion of contamination in laboratories and work spaces for diverse conditions of ventilation, contaminant release, local exhaust, safety equipment, occupancy and personnel activity. To accomplish the above task, a tracer gas is released into a test space and real-time measurements of gas concentration are made and recorded for various sample points. Data are analyzed to reveal tracer gas movement and dispersion. The results are applicable for estimating personnel exposure levels and for assessing facility and safety equipment design parameters. BIBLIOGRAPHIC REFERENCES: West, D. L.: Contaminant dispersion and dilution in a ventilated space. ASHRAE Transactions 83(I); 1977. (In Press). Chatigny, M. A., and West, D. L.: Ventilation rates: theoretical and practical considerations. In Idoine, L. S. (Ed).: Laboratory Ventilation for Hazard Control, Cancer Research Safety Monograph, Vol. 3. DHEW No. (NIH) 77-1293, 1977. (In Press).